 Image Number 10 for United States Patent #5376854.
A drive circuit for driving a piezoelectric element includes a transformer having a primary winding connected to a power source and a secondary winding connected to the piezoelectric element, a primary semiconductor element circuit connected to the primary winding for switching the current through the primary winding, and a secondary semiconductor element circuit connected to the secondary winding for switching the current through the secondary winding. A failure detection unit responsive to the potential at a predetermined point of the drive circuit is provided for detecting a failure in the piezoelectric apparatus and outputting a failure detection signal.
|